The aging process causes progressive deterioration in kidney structure and function. Aberrant generation of
reactive oxygen species has been implicated in both age-related and
ischemia-related tissue injury.
Vitamin E (VE), one of the most powerful and effective exogenous
antioxidants, prevents lipid peroxidation and protects against the effects of oxidative stress. The objective of this study was to determine the influence of age and VE on post-ischemic
acute renal failure (ARF). Young adult, middle-aged and aged male Wistar rats were maintained on three different 30-day diets: Normal, VE absent and VE supplemented. On day 30, urinary
protein and serum
cholesterol and VE were measured. On day 31, rats were subjected to 60' clamping of the left renal artery plus right
nephrectomy.
Inulin clearance (InCl) was performed 48 h after renal
ischemia.
Malondialdehyde (MDA) was measured in the cortex of normal and 48-h post-ischemic kidneys. Urinary
protein and serum
cholesterol were higher in aged rats than in other rats. With aging, InCl decreased progressively.
Vitamin E deficiency aggravated ARF. In middle-aged and aged rats, VE supplementation protected against ARF. In the absence of VE, MDA increased with age. In conclusion, our data suggest that ARF becomes more severe with age and that
ischemia/reperfusion injury is exacerbated when
antioxidant-scavenging ability of the kidney is impaired by VE deficiency. Supplementation with VE is essential for protecting aging kidneys against ischemic ARF.